• Radiation Oncology Journal
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• v.9 no.1
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• pp.37-45
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• 1991

In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthermia in canine liver were studied. Hyperthermia was externally adminsitered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. Group I (N=5) was heated with $42.5\pm0.5^{\circ}C$ 30 minutes, and Group II (N=5) was heated with $45\pm0.5^{\circ}C$ for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately after hyperthermia and T,14, and 28 days after treatment. Blood samples were obtained before treatment and W, 3,5, 7,14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in Group 1. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with $45^{\circ}C$ for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liverdamage dy heat of $42.5\pm0.5^{\circ}C$ for 30 minutes is reversible, and liver damage by heat of $45\pm0.5^{\circ}C$ for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in erder to apply hyperthermic treatment on human liver tumor safely, close obsewation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible.

• Progress in Medical Physics
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• v.24 no.2
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• pp.108-118
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• 2013

Currently, an arterial spin labeling (ASL) magnetic resonance imaging (MRI) technique does not routinely used in clinical studies to measure perfusion in brain because optimization of imaging protocol is required to obtain optimal perfusion signals. Therefore, the objective of this study was to investigate changes of perfusion-weighed signal intensities with varying several parameters on a pulsed arterial spin labeling MRI technique obtained from a 3T MRI system. We especially evaluated alternations of ASL-MRI signal intensities on special brain areas, including in brain tissues and lobes. The signal targeting with alternating radiofrequency (STAR) pulsed ASL method was scanned on five normal subjects (mean age: 36 years, range: 29~41 years) on a 3T MRI system. Four parameters were evaluated with varying: 1) the labeling gap, 2) the labeling delay time, 3) the labeling thickness, and 4) the slice scan order. Signal intensities were obtained from the perfusion-weighted imaging on the gray and white matters and brain lobes of the frontal, parietal, temporal, and occipital areas. The results of this study were summarized: 1) Perfusion-weighted signal intensities were decreased with increasing the labeling gap in the bilateral gray matter areas and were least affected on the parietal lobe, but most affected on the occipital lobe. 2) Perfusion-weighted signal intensities were decreased with increasing the labeling delay time until 400 ms, but increased up to 1,000 ms in the bilateral gray matter areas. 3) Perfusion-weighted signal intensities were increased with increasing the labeling thickness until 120 mm in both the gray and white matter. 4) Perfusion-weighted signal intensities were higher descending scans than asending scans in both the gray and white matter. We investigated changes of perfusion-weighted signal intensities with varying several parameters in the STAR ASL method. It should require having protocol optimization processing before applying in patients. It has limitations to apply the ASL method in the white matter on a 3T MRI system.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.9-14
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• 2005

Purpose: Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkinson-White) syndrome. Materials and Methods: Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECG with Fitzpatrick's algorithm or electrophysiologic study and radiofrequency catheter ablation. Results: Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients (mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent ($11.0{\pm}8.5%$, range:$3{\sim}35%$) and mild to moderate severity ($-71{\pm}42.7%$, range:$-2l7{\sim}-39%$) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patient with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Conclusion: Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but it did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

• Progress in Medical Physics
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• v.25 no.2
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• pp.89-94
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• 2014

We investigated whether regional hyperthermia (HT) increased post-surgical complications in patients with locally advanced rectal cancer treated with preoperative concurrent chemoradiotherapy (CCRT). Between 1996 and 2007, 205 patients treated with preoperative CCRT and curative surgery were evaluable for the analysis of acute and late toxicities. A total dose of 39.6 Gy or 45 Gy was delivered concurrently with one or two cycles of chemotherapy (5-fluorouracil, leucovorin). Eighty-eight patients received regional HT twice a week using an 8-MHz radiofrequency capacitive heating device. Surgery was performed 4~6 weeks after the completion of preoperative CCRT. The median age was 59 years (range, 18~83) and the median follow-up period was 61months (range, 2~191). The 5-year overall survival and complication-free survival rate of all patients was 77.4% and 73.7%, respectively. Early leakage, delayed leakage, anastomotic stricture, fistula, and small bowel obstruction occurred in 1.0%, 2.9%, 1.5%, 5.9%, and 17.1%, respectively. HT did not increase all kinds of complications. The 5-year complication-free survival rate was 71.8% in the non-HT group and 76.3% in the HT group (p=0.293). Regional HT did not increase postoperative complications in patients with locally advanced rectal cancer treated with preoperative CCRT followed by curative surgery.

• Journal of Chest Surgery
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• v.47 no.4
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• pp.367-372
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• 2014

Background: We compared the mid-term results of the Cox maze IV procedure using argon-based cryoablation with a procedure using $N_2O$-based cryoablation. Methods: From May 2006 to June 2012, 138 patients (mean age, $58.2{\pm}11.0$ years) underwent the Cox maze IV procedure. Eighty-five patients underwent the maze procedure using an $N_2O$-based cryoprobe (group N), and 53 patients underwent the maze procedure using an argon-based cryoprobe (group A). Bipolar radiofrequency ablation was concomitantly used in 131 patients. The presence of atrial fibrillation immediately, 6 months, 1 year, and 2 years after surgery was compared. Results: Early mortality occurred in 6 patients (4.3%). There were no differences in early mortality or postoperative complications between the two groups. Nineteen of 115 patients (16.5%) remained in atrial fibrillation at postoperative 12 months (14 of 80 patients (17.5%) in group N and 5 of 35 patients (14.3%) in group A, p=0.669). There were no differences in the number of patients who remained in atrial fibrillation at any of the time periods except in the immediate postoperative period. A multivariable analysis revealed that the energy source of cryoablation was not associated with the presence of atrial fibrillation at 1 year (p=0.862) and that a fine F wave (<0.1 mV) was the only risk factor predicting the presence of atrial fibrillation at 1 year (p<0.001, odds ratio=20.287). Conclusion: The Cox maze IV procedure using an argon-based cryoprobe was safe and effective compared with the maze procedure using an $N_2O$-based cryoprobe in terms of operative outcomes and the restoration of sinus rhythm for up to 2 years after surgery.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.59-68
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• 2008

This study was carried out to investigate the effects of the Inside end-taping (Inside-ET) and Outside end-taping (Outside-ET) treatments on prevention of drying defects during radiofrequency/vacuum (RF/V) drying domestic yellow poplar log cross section with size of 20~75 mm in thickness and 120~470 mm in diameter. The treatments of Inside-ET and Outside-ET were quite effective for producing sound log cross sections with thinner than 33 mm and smaller than 270 mm in diameter. Even the 60 mm- and 75 mm-thick log cross sections, if the diameter was smaller than 30 cm, it might expect preventing formation of border checks by appropriate end-taping treatments. The positions of the observed border checks differed in diameter ranging at a relative radius about 0.50~0.63 diameter, and it was estimated that it was necessary to select the border position of end-taping treatment properly according to the diameter of log cross sections. It was observed that the radius of 0.3 diameter was the critical location for pretreatment for preventing formation of border checks in the log cross section with middle diameter. There were severe border checks and V-shaped cracks in the log cross section with large diameter. This was because of the severe variation of moisture content along radial direction of natural characteristic of domestic yellow poplar.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.112-139
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• 2000

I examined and referred to literatures of every generations on the nicknames, causes, herb medications and acupucture treatments of ptosis(上胞下垂). And then the results were obtained as follows. We've compared and analyzed Occidental and Oriental medical causes, symptoms and treatments of Primary trigeminal neuralgia and wanted to get better effects by a cooperative analysis. So the examination and analysis of the recent treatment tendency and reference bibliography show the following results. 1. Trigeminal neuralgia is nerve systematic disease appearing in the distribution scope of trigeminal nerve. It's characterized by extreme pain accompanying with a repeated and simultaneous fit from several seconds to 1-2 minutes. 2. Though there are many hypothesis on the trigeminal neuralgia, but now many doctors agree that when trigeminal nerve is under the local out of sheath conditions resulting from receiving a chronic stimulus, and the nucleus of trigeminal nerve fire, owing to decrease of pain control function and abnormal occurrence of action potential, it would be appeared. 3. The Oriental medical name of trigeminal neuralgia is generally Dootong, Doopoong, Myuntong, Pyundootong, Pyundoopoong, and Myuntong is the nearest in Occidental medicine. 4. The Oriental medical cause of trigeminal neuralgia is usually divided into Wekam and Naesang. The first one is caused by Poonghan, Poongyul, Damhwa and wicked energy enter into the body, the mechanical energy is obstructed and can't move any more, so the pain appears by them. The other cause is the hurt by emotion. And it would be loss of the transportain of liver and obstructed, so result into Kanwulhwahwa, Kanpoongnaedong and the pain appears. 5. There are two methods of curing trigeminal neuralgia. As a medication, primary method is prescribing Carbamazepine and the second is using Phenytoin or Baclofen. And as a operation, Drug injection of trigeminal nerve, Amputation of branches of trigeminal nerve, Retrogasserian glycerol rhizotomy, Radiofrequency gangliolysis, Neurovascular decompression can be used. 6. There are several herb medicines for Trigeminal neuralgia. First, Chungung is good for Hwaejeetong, Keopoongjedam, Hwalhyuljeetong. Second, Jeongal, Jiryong, Okong is used for Sikpoonghekyung, Tongkyungjeetong. Third, Baekjee, Sesin, Cheonma, Manhyungja is efficacious in Sinonhepyo. Sanpoongjeetong. Fourth, for falling of liver's Wulhwa, Yongdamcho, Hyungge, Kukwha can be used. And also Saengjihwang, Hwangkm is good for going down the fever of Yangmyungwiyul and finally, Baekkangjam. Moryu can be effective for Jaumjamyang, Haekyungjitong. The other medicines can be used as assistant analgesics, and it also efficacious. 7. Generally the points of pain on the face and the points of Soyangkyung and Yangmyungkyung is used for Acupuntual therapy, because the two meridians passed on the face. Hakwan. Sabaek, Kwanryo, Keoryo, Hyubkeo, Taeyang, Jeechang, Younghyang, Eoyo, Chanjuk. Yangbaek. Sajukkong. Dooyoo, Kwangsangjum, Sengjang, Poongjee is used for taking near point and Joksamlee, Naejung, Habkok is used for taking distant point. 8. Dansam or Danggui injection which have a effect for Hwalhyulhwaeo, Sokyunghwalak and Vit B1, Vit B2, Vit B12, $2\%$ Hydrochloroprocaine, $1\%$ Lidocaine injection to pain point for local analgesics had so good effect. And external application and moxibustion are used for another treatment. 9. It proved that through mouse model, both Herb medication group and Drug medication group are efficacious for trigeminal neuralgia similarly and also the cooperative medication group shows more effective result than the only drug medication group.

• Journal of Korean Neurosurgical Society
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• v.59 no.6
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• pp.637-642
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• 2016

Objective : Although many treatment modalities have been introduced for trigeminal neuralgia (TN), the long-term clinical results remain unsatisfactory. It has been particularly challenging to determine an appropriate treatment strategy for patients who have responded poorly to initial therapies. We analyzed the surgical outcomes in TN patients who failed prior treatments. Methods : We performed a retrospective analysis of 37 patients with recurrent or persistent TN symptoms who underwent surgery at our hospital between January 2010 and December 2014. Patients with follow-up data of at least one year were included. The prior treatment modalities of the 37 patients included microvascular decompression (MVD), gamma knife radiosurgery (GKRS), and percutaneous procedures such as radiofrequency rhizotomy (RFR), balloon compression, and glycerol rhizotomy (GR). The mean follow-up period was 69.9 months (range : 16-173). The mean interval between the prior treatment and second surgery was 26 months (range : 7-123). We evaluated the surgical outcomes using the Barrow Neurological Institute (BNI) pain intensity scale. Results : Among the 37 recurrent or persistent TN patients, 22 underwent MVD with partial sensory rhizotomy (PSR), 8 received MVD alone, and 7 had PSR alone. Monitoring of the surgical treatment outcomes via the BNI pain intensity scale revealed 8 (21.6%) patients with a score of I, 13 (35.1%) scoring II, 13 (35.1%) scoring III, and 3 (8.2%) scoring IV at the end of the follow-up period. Overall, 91.8% of patients had good surgical outcomes. With regard to postoperative complications, 1 patient had transient cerebrospinal fluid rhinorrhea (2.7%), another had a subdural hematoma (2.7%), and facial sensory changes were noted in 8 (21.1%) patients after surgery. Conclusion : Surgical interventions, such as MVD and PSR, are safe and very effective treatment modalities in TN patients who failed initial or prior treatments. We presume that the combination of MVD with PSR enabled us to obtain good short- and long-term surgical outcomes. Therefore, aggressive surgical treatment should be considered in patients with recurrent TN despite failure of various treatment modalities.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.85-87
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• 2004

We fabricated flexible thermoradiotherapy probes to alternated combination with Interstitial hyperthermia and Brachyradiotherapy thermoradiotherapy probe was coated by gold plate on polyethylene brachytherapy probe. When Agar phantom was heated 15 minute with 30 W radiofrequency power, temperature increased as 5oC for polyethylene probe and 20oC for gold coated polyethylene probe. We observed that the 1 cm square array would heat a volume with a 1.25 cm radius circular field cross section to therapeutic temperatures (90% relative SAR using Tm) and the 2 cm square array with a 1.75 cm radius rectangular field with central inhomogeneity. With 2 cm long electrode implants, we observed that the 1 cm square array would heat a 3 cm long sagittal section to therapeutic temperature (90% relative SAR using Tm). The histopathological changes associated with RF heating of normal canine brains have been correlated with thermal distributions. RF needle electrode heating was applied for 50 min to generate tissue temperatures of 43${\circ}$C. We obtained a quarter of the heated tissue material immediately after heating and sacrificed at intervals from 7${\sim}$30 days. The acute stage was demonstrated by liquefactive necrosis, pyknosis of neuronal element in the gray matter. Mild gliosis occurring around the necrosis was demonstrated in the last sacrificed (days30)canine brain.

• Journal of Chest Surgery
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• v.48 no.5
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• pp.345-350
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• 2015

Background: Conventional stripping is considered to be the standard procedure for great saphenous vein (GSV) varicosities, but many other alternative treatments such as cryostripping, endovenous laser therapy (EVLT), radiofrequency ablation, and ultrasound-guided foam sclerotherapy have been developed. Among them, both cryostripping and laser therapy have been reported to be less traumatic, with lower rates of complications and recurrences when compared to conventional stripping. To compare the efficacy of these treatments, we have analyzed and compared the mid-term clinical outcomes of cryostripping and EVLT. Methods: Patients diagnosed with varicose veins of the GSV and treated with cryostripping or laser therapy between September 2008 and April 2013 were enrolled in this study. Duplex ultrasonography was used for the diagnosis and evaluation of varicosity and reflux, and the clinical-etiology-anatomy-pathophysiology classification was used to measure the clinical severity. The symptoms, Venous Clinical Severity Score (VCSS), recurrence rates, and complication rates of the cryostripping and laser therapy groups were analyzed and compared. Results: A total of 68 patients were enrolled in this study. 32 patients were treated with cryostripping, and 36 patients were treated with laser therapy. The median follow-up period was 29.6 months. Recurrence was noted in three patients from the cryostripping group and in two patients from the EVLT group. There was no difference in the VCSS score, operative time, duration of hospital stay, and complication rate between the cryostripping group and the EVLT group. Conclusion: The mid-term clinical outcomes of cryostripping were not inferior to those of EVLT. Further, considering its cost-effectiveness, cryostripping seems to be a safe and feasible method for the treatment of varicose veins.